A phase II trial of a new 5-fluorouracil derivative, BOF-A2 (Emitefur), for patients with advanced gastric cancer

The antineoplastic effects of BOF-A2 (Emitefur), a 5-fluorouracil (5-FU) derivative, in capsule form were assessed in patients with advanced gastric cancer, in a multicenter late phase II study and at 11 different hospitals. The patients were scheduled to receive a minimum of two courses of BOF-A2 orally, with each course of BOF-A2 consisting of 200mg twice daily for 2 weeks followed by a withdrawal period of 2 weeks. Of the 24 patients entered into the study, the clinical response was able to be evaluated in 21 cases and the toxicity was determined in 23 cases. Eleven (45.8%) patients had been treated previously with other anticancer drugs. There was a 38.1% (8/21) response rate (95% confidence interval 17.3-58.9) with 1 (4.8%) complete response (CR) and 7 (33.3%) partial responses (PR), and these responses continued for over 4 months. In particular, the response rate for the primary lesion was 33.3% (3/9). No change (NC) in the disease was observed in 5 (23.8%) patients, and in 8 (38.1%) the disease progressed (PD). At the time of analysis, the median survival of the responders was 13 months, while that of the NC group was 7 months and that of the PD group was 2 months. The major adverse events consisted of gastrointestinal symptoms, myelosuppression, and skin symptoms, while toxicities of grade 3 or more occurred in 26.1% (6/23). These toxicities all resolved within 1-37 days after discontinuing the drug treatment. Based on the above findings, BOF-A2 is considered to be a promising anticancer drug for patients with advanced gastric cancer.